Apparatus for the manufacture of ceramically bonded shaped articles from granulates of inflatable mineral material

ABSTRACT

An apparatus for the production of ceramically bonded shaped bodies of granulates of an inflatable mineral material, particularly clay, which comprises a combustion chamber tapering in opposite directions, with a holding device for a fire box movable through the combustion chamber and provided with a bottom grate, located in the plane of the common maximum cross-section of the chamber, and a system of conduits adjoining ends of the combustion chamber for recycled heating-and combustion-gases, in the circuit being provided at least one burner device, a circulating device and a reversing device for reversing redirection of flow of the gases through the combustion chamber. A blower maintains the required pressure in the system of conduits, and arranged directly in series, with two chambers connected via a restriction of a continuously operating regenerator operated with a circulated heat-retainer mass and the combustion chamber in the parallel circuit is connected at its ends on both sides of the restriction to the regenerator.

United States Patent [1 1 Briem [75] Inventor: Karl Briem,tBraunschweig,

Germany [73] Assignee: Firma Zytan Thermochemische Verfahrenstechnik GmbII & Co., I(.G.-, Braunschweig, Germany [22] Filed: Nov. 9, 1972 [21] Appl. No.: 305,150

[30] Foreign Application Priority Data Nov. 10, 1971 Germany P 21 55 933.1

[52] US. Cl. 432/101, 432/215 [51] Int. Cl. F27b 1/02, F27b 15/00 [58] Field of Search 432/13, 27, 101,180, 215

[5 6] References Cited UNITED STATES PATENTS 2,571,749 10/1951 Norton, Jr. 432/27 FOREIGN PATENTS OR APPLICATIONS 755,305 Great Britain 432/27 Feb. 19, 1974 Primary Examiner--John J. Camby Attorney, Agent, or FirmEmest G. Montague [57] ABSTRACT An apparatus for the production of ceramically bonded shaped bodies of granulates of an inflatable mineral material, particularly clay, which comprises a combustion chamber tapering in opposite directions, with a holding device for a fire box movable through the combustion chamber and provided with a bottom grate, located in the plane of the common maximum cross-section of the chamber, and a system of conduits adjoining ends of the combustion chamber for recycled heating-and combustion-gases, in the circuit being provided at least one burner device, a circulating device and a reversing device for reversing redirection of flow of the gases through the combustion chamber. A blower maintains the required pressure in the system of conduits, and arranged directly in series, with two chambers connected via a restriction of a continuously operating regenerator operated with a circulated heat-retainer mass and the combustion chamber in the parallel circuit is connected at its ends on both sides of the restriction to the regenerator.

8 Claims, 3 Drawing Figures PATENTEU F551 9974 3, 792, 962

APPARATUs FOR THE MANUFACTURE OF CERAMICALLY BONDED SHAPED ARTICLES FROM GRANULATES F INFLATABLE MINERAL MATERIAL The present invention relates to an apparatus for the manufacture of ceramically bonded shaped articles from granulates of inflatable mineral material, and particularly clay, consisting of a combustion chamber which preferably tapers in opposite directions andd has a holding device for a fire box which is movable through the combustion chamber and is provided with a bottom grate, the fire box being located in the plane of the common largest cross-section of the chamber, and of a system of conduits connected to the two ends of the combustion chamber for recycled heating and reaction gases, at least one burner device, a circulating and possibly a reversing device for reversing the direction of flow of the gases through the combustion chamber being provided in said circuit.

In the known apparatus of the type operated the two frustoconical chamber sections of the flow chamber serve for pressure equalization and are connected to a system of conduits in which the gases which have been heated to a high temperature by the burner can be circulated in a closed circuit. In this connection, for the better distribution of the combustion gas over the entire cross-section of the burner in the chamber there are provided, on both sides of the plane of the largest cross-section, flow obstacles which distribute the fuel gas fed over the entire surface of the granulates contained in the firebox.

In the apparatus described, the heated gas serves on the one hand as heat carrier for heating the material present in the fire box and on the other hand as a chemical agent for controlling the inflating behavior of the granulates and for controlling the processes in the ceramic bonding which occurs after the inflating of the granulates. In the known apparatus, the is gases are fed alternately to invention opposite flat sides of the fire box to the granulate filling in order to obtain as uniform as possible an action on the granulates by the heating gases both during the'inflation and during the ceramic bonding, and thus obtain ceramically bonded shaped bodies of a fine, uniform cell structure throughout.

in the process carried out with the known apparatus, the factors of influence such as value of the temperature which lies in the range of l,OOO to l200C, depending on the nature of the material to be treated, the duration of the time of action and the velocity of the gas, as well as the composition of the heating and reaction gases, can be varied only within relatively narrow limits coresponding to the initial properties of the materials used in order to obtain specific mechanical and physical properties on the part of the finished shaped body. It affords great difficulty to bring the specific temperature and chemical composition of the gases precisely to the desired values and, during the course of the process, to vary them rapidly and dependably in accordance with a given reproducible law.

It s one object of the present inventionn to provide an apparatus for manufacturing ceramically bonded shaped bodies from granulates of inflatable mineral material which develops the apparatus described above in such a manner, that the mentioned difficulties are overcome and that it is possible with the apparatus to produce fired shaped bodies which are characterized by a high uniformity of their properties over their entire cross-section and can be produced in dependable manner in the desired quality reproducibly even in continuous process.

It is another object of the present invention wherein the two chambers of a continuously operating regenerator are operated with a circulated retainer mass which are connected to each other via a constriction directly in series with a blower or the like, which maintains the required pressure in the system of conduits and by connecting the combustion chamber in parallel with its two ends on either side of the constriction in the regenerator. In this connection, a cooling device is advantageously inserted in the main gas circuit in series with the blower, by which cooling device the adjustment of the temperature is obtained when it is necessary to reduce the temperature of the combustion gas.

It is advantageous to arrange a dust precipitator for the gas, for instance a cyclone, in series with the blower so that the retainer mass remains free of deposits of dust and the filling up of the empty spaces with dust is prevented. The connecting end of at least the inflow side of the combustion chamber preferably has a chamber which widens in the direction away from the mount for the fire box, in which chamber the burner device is arranged shielded from the combustion chamber. By this burner arrangement, the unavoidable losses of energy within the combustion gas circulating in a closed circuit are counteracted without transfer of radiant energy to the upper layer of the combustion material in the form box. At the same time, by means of the burner, the temperature of the gases present in the flow to the fire box can be controlled in sensitive and rapid fashion and a corresponding change in the chemical composition of the combustion gases can also be obtained by varying the burner adjustment.

Through the main circuit and the parallel circuit for the combustion gases, there results a separate flow of individually adjusted temperature. The arrangement of the unit consisting of combustion chamber and regenerator with all accessories. can also operate continuously without change in direction of the flow.

Another essential feature for the further development of the present invention is that the receiver in the plane of the largest cross-section of the combustion chamber has a ring-shaped pocket, open towards the axis of the chamber, for guiding and covering the edge of the fire box with respect to the combustion gases. The pocket is preferably so designed that it forms a seal with the edge of the fire box, so that the two sections of the combustion chamber which widen in the direction towards the largest cross-section are sealed off with respect to each other and the heating and reaction gases must flow completely through the mass of granulate contained in the fire box.

The combustion chamber can in this connection also be designed as a chamber with uniform cross-section over substantially its entire height, adjoining which cross-section there are first of all sections of tapering cross-section serving as diffuser or collector and then widening chamber sections for the feeding and discharge of the gases.

It is of particular practical importance for the pocket to have heat-conduction surfaces which are in contact with the edge of the fire box and serve for the removal of heat. For the precise control of the removal of the heat, the heat-removal surfaces are preferably connected to a positive cooling system.

With these and other objects in view, which will become apparent in the following detailed description, the present invention, which is shown by example only, will be clearly understood in connection with the accompanying drawing in which:

FIGS. 1a, lb and 1c schematic vertical sections, constituting the main part of the apparatus in accordance with the present invention, are shown partially stylized and partly inside elevations.

Referring now to the drawings, corresponding to the Figures, the apparatus consists of a combustion chamber 1 and a regenerator 2, the latter being arranged in a main circuit 3 for circulated fuel gases and the combustion chamber 1 being arranged in a parallel circuit 4 for the combustion gases, which parallel circuit being connected to the regenerator 2.

The combustion chamber 1 consists of two chamber sections 5 and 6 which taper in opposite directions and by which combustion chamber regions 7 and 8 are formed. ln the plane 9 of the common maximum crosssection of the combustion chamber there is arranged a mount for a fire box 13 with a bottom grate l6 and filled with granulate 15 of inflatable material. The mount consists ofa ring-shaped pocket 12 lying outside the cross-scction of the combustion chamber and open towards the axis of the combustion chamber, said pocket having guide surfaces 10 which cooperate with the edge region 14 of the fire box 13 in the manner which will be described further below. The guide surfaces 10 of the ring-shaped pocket 12 are connected in the example shown to a cooling system 11, by which the temperature of the guide surfaces 10 can be set to a predetermined value.

Adjoining the narrow end of the upper chamber 7 is another chamber 19, the cross-section of which is widened by the wall 17. Connected to the chamber 19 is a conduit 23 which is part of the parallel circuit 4. Furthermore, a burner arrangement 21 is provided such in this chamber, that on the one hand the combustion gases produced by the open burner mix dependably with the gases fed through the conduit 23, while on the other hand the material being fired itself is protected from the open burner flames being radiated against it.

Since the arrangement described can also be opeated in the known manner described above, in which the combustion gases are fed to the largest cross-section of the combustion chamber alternately from the two sides, the narrow end of the lower combustionchamber section 8 also has a chamber which is widened by the wall 18 and to which the conduit 24 of the parallel circuit 4 and a burner device 22 are connected.

The two lines 23, 24 of the parallel circuit can be connected for the aforementioned alternate operation to the regenerator via a reversing device 25.

The regenerator shown operates continuously and is operated with aflowable heat-retainer mass, which is kept continuously in circulation and is indicated at 50. This retainer mass is withdrawn from the regenerator through a corresponding air lock at 34 and discharged in the direction of the arrow 51 and fed to an elevator 36 which feeds the retainer mass again to a feed 35 provided with a corresponding air lock at the upper end of the regenerator.

The regenerator approximately at its midheight has a strong constriction 33 by which an upper regenerator chamber 31 is in communication with a corresponding lower regenerator chamber 32. The constriction is so dimensioned that the retainer mass can pass essentially without substantial resistance from the upper chamber 31 into the lower chamber 32, while the passage of the gases is strongly throttled by the constriction 33.

The regenerator 2 has at its upper end 43 a connection for removal of the combustion gases and at its lower end a feed connection 38 for the return of the combustion gases, a corresponding grate bottom conducting the retainer mass being associated furthermore with the feed. By the connections described, the regenerator is connected in the main circuit 3 for the combustion gases. This main circuit contains, in series with the regenerator, a blower 41 which sees to the required pressure in the circulating system. Furthermore, a cooler 42 can also be provided in the main circuit in order to counteract any possible overheating. The main circuit also has a dust remover in the form of a cyclone 72, so that a continuous discharge of the dust entrained by the heating and reaction gases takes place.

The parallel circuit 4 is connected via the connectlons 28 and 30 and the conduits 26 and 27 to the main circuit 3 via the regenerator 2, the two connections lying directly above and below the constriction 33 of the regenerator. Annular distributor sections 28a and 30a, respectively, can also be associated with the con nections.

In the main circuit 3 the gases flow always in the direction indicated by the arrows. In the parallel circuit 4, behind the reversing device 25, the direction of flow indicated by the arrows can be reversed by means of the reversing device.

In the example shown, the combustion gases are fed from the chamber 6 via the conduit 24, the reversing device 25 and the conduit 27 to the connection 30 lying above the constriction 33, and there come against the cooler retainer mass which is ready to receive the heat present in the gases. The gases which thereby cool further are discharged at 43 from the regenerator chamber 31, possibly cooled at 42 and the dust precipitated from them in the cyclone 72, and forced at the desired pressure via the blower 41 at the bottom into the regenerator chamber 32. In this chamber there is contained the retainer mass which has been heated by the recycled combustion gases and which now heat the coller gas again to the desired temperature. Depending on the conditions of flow selected, the constriction 33, which is filled with the heat-retainer mass forms a resistance to flow which sees to it that a predetermined quantity of the heated gases passes at predetermined speed at 28 into the parallel circuit 4 and is fed via the conduit 26, the reversing device 25 and the conduit 23 to the chamber 19 in which the gas is subjected to the action of the burner device 21 which is screened off by the protruding wall 17. In this way the temperature of the inwardflowing gases can be accurately corrected and at the same time the chemical composition of the inwardflowing gases can be controlled in desired fashion. The heating and reaction gases which have been treated in this manner pass into the combustion chamber section 7 and there come against the mass of granulate in the fire box 13. All gases must flow through this mass of granulate if the fire box forms a dependable seal with the walls 10 of the pocket 12.

By means of the blower 41, the cooler 42 and the burner 21, the properties of the fuel gases can be rapidly and accurately controlled and changed in desired manner during the treatment of the material. At the same time, the heat contained'in the system is always again utilized extensively, so that the treatment of the material can take place in a very economical manner. The discharge of excess gases, particularly with the burner devices 21, 23 connected, can take place by suitable adjustment via a discharge-gas connection 74.

By the measures described above there is created the prerequisite for the treatment of the masses of granulate, and particularly the ceramic bonding of the granulates can be carried out in highly reproducible manner in the fire boxes, so that shaped bodies of constant properties and thus high. quality can be obtained.

While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only.

I claim:

1. An apparatus for the production of ceramically bonded shaped bodies of granulates of an inflatable mineralmaterial, particularly clay, comprising a fire box,

a combustion chamber including two chamber sections tapering in opposite directions, and having ends of smaller cross-section, with a holding and guiding device for said fire box movable into and out of said combustion chamber and provided with a bottom grate and extending in the plane of the common maximum cross-section of said chamber sections, and

a system of conduits adjoining said ends of said combustion chamber for passage therethrough of recycled heating and combustiongases, comprising at least one burner, a blower means, and a reversing means for reversing the direction of flow of said gases through said combustion chamber,

a continuously operating regenerator having a heat absorber chamber and a heat dissipating chamber containing a circulated heat retentive material and a constriction communicating said two chambers,

said two chamber sections of said combustion chamber being in series with said burner and communicating via said reversing means with said respective chambers of said regenerator at opposite sides of said constriction,

said blower means for maintaining the required pressure in said system of conduits, being arranged in series to said two chambers of said regenerator, and

said blower means being arranged in parallel to said reversing means.

2. The apparatus, as set forth in claim 1, which includes a cooler connected in the gas main circuit in series with said blower means.

3. The apparatus, as set forth in claim 2, which includes a duct precipitation for said gas arranged in series with said blower means.

4. An apparatus for the production of ceramically bonded shaped bodies of granulates of an inflatable mineral material, particularly clay, comprising a combustion chamber tapering in opposite directions, with a holding device for a fire box movable through said combustion chamber and provided with a bottom grate, located in the plane of the common maximum cross-section of said chamber, and

a system of conduits adjoining ends of said combustion chamber for recycled heatingand combustiongases, in said circuit being provided at least one burner device, a circulating device and reversing device for reversing redirection of flow of said gases through said combustion chamber,

a blower, maintaining the required pressure in said system of conduits, arranged directly in series, with two chambers connected via a restriction of a continuously operating regenerator operated with circulated heating retainer mass and said combustion chamber in the parallel circuit being connected at its ends on both sides of said restriction to said regenerator,

the connecting end of at least the inflow side of said combustion chamber has a chamber widening in directions away from said mount for said first box, and

said burner device is arranged in said chamber covered off from the adjacent combustion chamber reaction.

5. The apparatus, as set forth in claim 4, wherein said reversing device is arranged in said parallel circuit between said regenerator and said combustion chamber.

6. The apparatus, as set forth in claim 5, wherein said receiver in the plane of the largest cross section of the combustion chamber has a ring-shaped jacket, open towards the axis of said chamber, for guiding and covering said fire box edge with respect to the heating and reaction gases.

7. The apparatus, as set forth in claim 6, wherein said pocket cooperates in sealing fashion with the edge of said fire box.

8. The apparatus, as set forth in claim 7, wherein said pocket has heat-removal surfaces which are in contact with said fire-box edge and connected to a cooling system. =l= 

1. An apparatus for the production of ceramically bonded shaped bodies of granulates of an inflatable mineral material, particularly clay, comprising a fire box, a combustion chamber including two chamber sections tapering in opposite directions, and having ends of smaller cross-section, with a holding and guiding device for said fire box movable into and out of said combustion chamber and provided with a bottom grate and extending in the plane of the common maximum cross-section of said chamber sections, and a system of conduits adjoining said ends of said combustion chamber for passage therethrough of recycled heating and combustion- gases, comprising at least one burner, a blower means, and a reversing means for reversing the direction of flow of said gases through said combustion chamber, a continuously operating regenerator having a heat absorber chamber and a heat dissipating chamber containing a circulated heat retentive material and a constriction communicating said two chambers, said two chamber sections of said combustion chamber being in series with said burner and communicating via said reversing means with said respective chambers of said regenerator at opposite sides of said constriction, said blower means for maintaining the required pressure in said system of conduits, being arranged in series to said two chambers of said regenerator, and said blower means being arranged in parallel to said reversing means.
 2. The apparatus, as set forth in claim 1, which includes a cooler connected in the gas main circuit in series with said blower means.
 3. The apparatus, as set forth in claim 2, which includes a duct precipitation for said gas arranged in series with said blower means.
 4. An apparatus for the production of ceramically bonded shaped bodies of granulates of an inflatable mineral material, particularly clay, comprising a combustion chamber tapering in opposite directions, with a holding device for a fire box movable through said combustion chamber and provided with a bottom grate, located in the plane of the common maximum cross-section of said chamber, and a system of conduits adjoining ends of said combustion chamber for recycled heating- and combustion- gases, in said circuit being provided at least one burner device, a circulating device and reversing device for reversing redirection of flow of said gases through said combustion chamber, a blower, maintaining the required pressure in said system of conduits, arranged directly in series, with two chambers connected via a restriction of a continuously operating regenerator operated with circulated heating retainer mass and said combustion chamber in the parallel circuit being connected at its ends on both sides of said restriction to said regenerator, the connecting end of at least the inflow side of said combustion chamber has a chamber widening in directions away from said mount for said first box, and said burner device is arranged in said chamber covered off from the adjacent combustion chamber reaction.
 5. The apparatus, as set forth in claim 4, wherein said reversing device is arranged in said parallel circuit between said regenerator and said combustion chamber.
 6. The apparatus, as set forth in claim 5, wherein said receiver in the plane of the largest cross section of the combustion chamber has a ring-shaped jacket, open towards the axis of said chamber, for guiding and covering said fire box edge with respect to the heating and reaction gases.
 7. The apparatus, as set forth in claim 6, wherein said pocket cooperates in sealing fashion with the edge of said fire box.
 8. The apparatus, as set forth in claim 7, wherein said pocket has heat-remOval surfaces which are in contact with said fire-box edge and connected to a cooling system. 